A load warning system for use with a vehicle having a load-support portion, a frame, and a vehicle-support portion movably coupled to the frame. The system has an engagement portion mountable to the vehicle-support portion or the frame and is movable therewith as a unit. A load indicator is mountable to the other one of the vehicle-support portion or the frame, and is spaced apart from the engagement portion when in a first position. The load indicator moves to a second position and engages the engagement portion when the frame moves a selected distance in response to the load applied to the load-support portion. The load indicator provides a signal upon being moved to the second position. A warning indicator is coupled to the load indicator and provides an improper load warning to a user in response to the signal from the load indicator.